Reduction of aldehydes in amine catalysts

ABSTRACT

The present disclosure provides a method for reducing the aldehyde content in an amine catalyst by treating the amine catalyst with a treating agent selected from a non-cyclic amide substituted with an isocyanate reactive group, a guanidine substituted with an isocyanate reactive group, a polyether amine adducted with a urea compound or a guanidine compound, a free radical scavenger and a mixture thereof. The treated amine catalyst may then be used in the production of polyurethane materials which exhibit reduced aldehyde emissions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the National Phase of International ApplicationPCT/US2015/011163 filed Jan. 13, 2015 which designated the U.S. andwhich claims priority to U.S. App. Ser. No. 62/098,380 filed Dec. 31,2014. The noted applications are incorporated herein by reference.

FIELD OF THE INVENTION

The present disclosure is directed to amine catalysts exhibiting lowlevels of aldehydes and to polyurethane materials produced using suchamine catalysts.

BACKGROUND INFORMATION

Emissions from polyurethane foam are a concern in many applications,especially when workers or end users are exposed to the foam within anenclosed space. Aldehyde emissions, such as formaldehyde, are aparticular cause of concern. To reduce such aldehyde emissions, severalmethods have been developed to reduce the aldehyde content of the rawmaterials used in producing polyurethane foam. For example: U.S. Pat.No. 7,879,928 discloses a method for preventing the formation ofaldehyde compounds in polyether or polyester polyols by incorporating aphenolic antioxidant and an aminic antioxidant into the polyol; U.S.Pat. Publ. No. 2009/0227758 discloses a method of reducing aldehydes inpolyols and polyisocyanates by reacting the polyol with anoxazolidine-forming amino alcohol and the polyisocyanate with anitroalkane; U.S. Pat. App. No. 2006/0141236 discloses the addition of ahydrazine to a polyol to act as an aldehyde-scavenger; U.S. Pat. App.No. 2008/0281013 discloses a method for reducing aldehyde emissions froma polyurethane foam by the addition of hydrogen sulfites and disulfitesto the polyol component; U.S. Pat. App. No. 2009/0326089 discloses theuse of a compound having a carbon amide group and a nitrile group toproduce foams having a lowered emission of formaldehyde; WO2009/114329teaches the addition of an oxazolidine-forming amino alcohol to a polyoland a nitroalkane to a polyisocyanate to reduce aldehyde emissions priorto their reaction in the production of a polyurethane; U.S. Pat. App.No. 2013/0203880 which teaches the addition of apolyhydrazodi-carbonamide polyol to the polyol component or a trimerizedhexamethylene diisocyanate to the polyisocyanate component results infoams exhibiting decreased aldehyde emissions; and U.S. Pat. No.5,506,329 discloses the use of certain aldimine oxazolidine compoundsfor scavenging formaldehyde from polyisocyanate-containing preparations.

In addition to polyols and polyisocyanates, amine catalysts are oftenutilized as a raw material in the production of polyurethane foam. Thealdehydes found in amine catalysts may be derived from a variety ofsources, for example, they may be present as a contaminant from themanufacture of the amine, or they may result from the oxidation or freeradical attack of various carbon segments of the amine during storage.Methods to reduce the aldehyde content in amine catalysts include theuse of inert gas (see U.S. Pat. Publ. No. 2013/0085193), primary amines(see U.S. Pat. Publ. No. 2011/0009513) free radical scavengers (see U.S.Pat. Publ. No. 2012/0271026) and combining an amine which has urea,amide, secondary-amine, primary amine or secondary-hydroxylfunctionality with a carboxylic diacid or triacid (see U.S. Pat. Publ.No. 2013/0137787). Additionally, DE102008025005 teaches the use of ureananoparticles in the treatment of amine catalysts to removeformaldehyde; however, when the amine catalyst is subsequently used inthe production of foam, the urea is found as an emission in the foam andtherefore the foam will generally fail environmental specifications fortotal emissions.

Despite the state of the art, there is a continuing need for developingother inexpensive and effective methods to reduce the aldehyde contentin amine catalysts. Preferably, such methods do not result insignificant changes to the properties or performance of the aminecatalyst or the resulting polyurethane foam. Moreover, preferably suchmethods do not produce other fugitive species which may provideadditional environmental, health and safety issues to the amine catalystand resulting polyurethane foam.

SUMMARY OF THE INVENTION

The present disclosure relates to a method for reducing the aldehydeimpurities from an amine catalyst by treating the amine catalyst with atreating agent selected from a non-cyclic amide substituted with anisocyanate reactive group, a guanidine substituted with an isocyanatereactive group, a polyether amine adducted with a urea compound or aguanidine compound, a free radical scavenger and a mixture thereof andsubjecting the resulting mixture to conditions such that the level ofaldehyde impurities in the amine catalyst is reduced.

In a further embodiment, the present disclosure provides a method forreducing the aldehyde emissions from a polyurethane material by reactinga polyisocyanate and polyol in the presence of the treated aminecatalyst above.

In a still further embodiment, the present disclosure provides apackaged product comprising a container and a catalyst mixture withinthe container, the catalyst mixture comprising an amine catalyst and atreating agent selected from a non-cyclic amide substituted with anisocyanate reactive group, a guanidine substituted with an isocyanatereactive group, a polyether amine adducted with a urea compound or aguanidine compound, a free radical scavenger and a mixture thereof andwherein the amine catalyst and treating agent have been subjected toconditions such that the level of aldehyde impurities in the aminecatalyst has been reduced.

DETAILED DESCRIPTION

If appearing herein, the term “comprising” and derivatives thereof arenot intended to exclude the presence of any additional component, stepor procedure, whether or not the same is disclosed herein. In order toavoid any doubt, all formulations claimed herein through use of the term“comprising” may include any additional additive, adjuvant, or compound,unless stated to the contrary. In contrast, the term, “consistingessentially of” if appearing herein, excludes from the scope of anysucceeding recitation any other component, step or procedure, exceptingthose that are not essential to operability and the term “consistingof”, if used, excludes any component, step or procedure not specificallydelineated or listed. The term “or”, unless stated otherwise, refers tothe listed members individually as well as in any combination.

The articles “a” and “an” are used herein to refer to one or to morethan one (i.e. to at least one) of the grammatical object of thearticle. By way of example, “a free radical scavenger” means one freeradical scavenger or more than one free radical scavenger.

The phrases “in one embodiment,” “according to one embodiment,” and thelike generally mean the particular feature, structure, or characteristicfollowing the phrase is included in at least one embodiment of thepresent invention, and may be included in more than one embodiment ofthe present invention. Importantly, such phrases do not necessarilyrefer to the same embodiment.

If the specification states a component or feature “may”, “can”,“could”, or “might” be included or have a characteristic, thatparticular component or feature is not required to be included or havethe characteristic.

For methods of treating an amine catalyst, the term “treating” includesplacing a component onto the amine catalyst using any suitable mannerknown in the art, including, but not limited to, pumping, injecting,pouring, releasing, displacing, squeezing, spotting, or circulating thecomponent onto the amine catalyst.

The term “isocyanate reactive group” as used herein includes any groupor moiety containing an active hydrogen group or moiety. For thepurposes of this disclosure, an active hydrogen containing group refersto a group containing a hydrogen atom which, because of its position inthe molecule, displays significant activity according to the Zerewitnofftest described by Wohler in the Journal of the American ChemicalSociety, Vol. 49, page 3181 (1927). IIIustrative of such active hydrogengroups are —COOH, —OH, —NH₂, and —NH.

The term “non-cyclic amide” means an amide compound that does notcomprise a closed ring structure.

The term “polyamine” means a compound comprising two or more primary orsecondary amine groups per molecule.

The term “cyclic group” means a closed ring hydrocarbon group that isclassified as an alicyclic group, aromatic group, or heterocyclic group.The term “alicyclic group” means a cyclic hydrocarbon group havingproperties resembling those of aliphatic groups. The term “aromaticgroup” means a mono-, di-, or polynuclear aromatic hydrocarbon group.The term “heterocyclic group” means a closed ring hydrocarbon in whichone or more of the atoms in the ring is an element other than carbon(for e.g., nitrogen, oxygen, sulfur, etc.).

In one aspect, the present disclosure provides a method for reducing thealdehyde content in an amine catalyst by treating an amine catalystcontaining one or more aldehyde impurities with a treating agentselected from a non-cyclic amide substituted with an isocyanate reactivegroup, a guanidine substituted with an isocyanate reactive group, apolyether amine adducted with a urea compound or a guanidine compound, afree radical scavenger and a mixture thereof to form a catalyst mixtureand subjecting the catalyst mixture to conditions such that the level ofaldehyde impurities in the amine catalyst is reduced.

In another aspect, the present disclosure provides a method for reducingaldehyde emissions from a polyurethane material comprising (i) treatingan amine catalyst containing one or more aldehyde impurities with atreating agent selected from a non-cyclic amide substituted with anisocyanate reactive group, a guanidine substituted with an isocyanatereactive group, a polyether amine adducted with a urea compound or aguanidine compound, a free radical scavenger and a mixture thereof toform a catalyst mixture and subjecting the catalyst mixture toconditions such that the level of aldehyde impurities in the aminecatalyst are reduced and (ii) reacting a polyol with a polyisocyanate inthe presence of the catalyst mixture from step (i) to form apolyurethane material.

In still another aspect, there is provided a packaged product comprising(i) a container having an outlet and (ii) a catalyst mixture within thecontainer comprising a treating agent selected from a non-cyclic amidesubstituted with an isocyanate reactive group, a guanidine substitutedwith an isocyanate reactive group, a polyether amine adducted with aurea compound or a guanidine compound, a free radical scavenger and amixture thereof and an amine catalyst containing one or more aldehydeimpurities wherein the catalyst mixture has been subjected to conditionssuch that the level of aldehyde impurities in the amine catalyst hasbeen reduced. The packaged product may be stored for a long period oftime (for e.g. at least about 1 month) and can be used in themanufacture of a polyurethane material.

The present disclosure therefore provides an inexpensive and effectiveway to reduce the level of aldehyde impurities, such as formaldehyde, inan amine catalyst through treatment with a non-cyclic amide substitutedwith an isocyanate reactive group, a guanidine substituted with anisocyanate reactive group, a polyether amine adducted with a ureacompound or a guanidine compound, a free radical scavenger or acombination thereof. Moreover, the treated amine catalyst exhibitsstable color over time as compared to color increase exhibited byuntreated amine catalysts. After treatment, the catalyst mixturecomprising the amine catalyst and treating agent can be used to catalyzethe reaction between a polyol and polyisocyanate to produce apolyurethane material that exhibits reduced aldehyde emissions. It hasbeen surprisingly found that by incorporating an isocyanate reactivegroup having an active hydrogen compound that is more reactive than thehydrogen compound of a urea group onto the treating agent allows thetreating agent to remain bound in the polyurethane material thuspreventing it from becoming a volatile organic contaminant, yet allowingit to still remain active as a scavenger for aldehydes.

The amine catalyst of the present disclosure may be any amine useful asa catalyst in a polyurethane material formation reaction. According toone embodiment, the amine catalyst is an amine containing one or moretertiary amino groups. Examples include, but are not limited to,bis-(2-dimethylaminoethyl)ether (JEFFCAT® ZF-20 catalyst),N,N,N′-trimethyl-N′-hydroxyethylbisaminoethylether (JEFFCAT® ZF-10catalyst), N-(3-dimethylaminopropyl)-N, N-diisopropanolamine (JEFFCAT®DPA catalyst), N, N-dimethylethanolamine (JEFFCAT® DMEA catalyst),triethylene diamine (JEFFCAT® TEDA catalyst), blends ofN,N-dimethylethanolamine and triethylene diamine (such as JEFFCAT® TD-20catalyst), N,N-dimethylcyclohexylamine (JEFFCAT® DMCHA catalyst),benzyldimethylamine (JEFFCAT® BDMA catalyst),pentamethyldiethylenetriamine (JEFFCAT® PMDETA catalyst),N,N,N′,N″,N″-pentamethyldipropylenetriamine (JEFFCAT® ZR-40 catalyst),N,N-bis(3-dimethylaminopropyl)-N-isopropanolamine (JEFFCAT® ZR-50catalyst), N′-(3-(dimethylamino)propyl-N,N-dimethyl-1,3-propanediamine(JEFFCAT® Z-130 catalyst), 2-(2-dimethylaminoethoxy)ethanol (JEFFCAT®ZR-70 catalyst), N,N,N′-trimethylaminoethyl-ethanolamine (JEFFCAT® Z-110catalyst), N-ethylmorpholine (JEFFCAT® NEM catalyst), N-methylmorpholine(JEFFCAT® NMM catalyst), 4-methoxyethylmorpholine, N,N′dimethylpiperzine (JEFFCAT® DMP catalyst),2,2′dimorpholinodiethylether (JEFFCAT® DMDEE catalyst),1,3,5-tris(3-(dimethylamino)propyl)-hexahydro-s-triazine (JEFFCAT® TR-90catalyst), 1-Propanamine, 3-(2-(dimethylamino)ethoxy), substitutedimidazoles such as 1,2-dimethlyimidazol and1-methyl-2-hydroxyethylimidazole, N,N′-dimethylpiperazines orbis-substituted piperazines such aminoethylpiperazine, N,N′,N′-trimethylaminoethylpiperazine or bis-(N-methyl piperazine)urea,N-methylpyrrolidines and substituted methylpyrrolidines such as2-aminoethyl-N-methylpyrrolidine or bis-(N-methylpyrrolidine)ethyl urea,3-dimethylaminopropylamine, N,N,N″,N″-tetramethyldipropylenetriamine,tetramethylguanidine, 1,2 bis-diisopropanol. Other examples of aminecatalysts include N-alkylmorpholines such as N-methylmorpholine,N-ethylmorpholine, N-butylmorpholine and dimorpholinodiethylether,N,N′-dimethylaminoethanol, N, N-dimethylamino ethoxyethanol,bis-(dimethylaminopropyl)-amino-2-propanol,bis-(dimethylamino)-2-propanol, bis-(N,N-dimethylamino)ethylether;N,N,N′-trimethyl-N′hydroxyethyl-bis-(aminoethyl)ether,N,N-dimethylaminoethyl-N′-methyl amino ethanol,tetramethyliminobispropylamine and combinations thereof. Theaforementioned JEFFCAT® catalysts are available from HuntsmanPetrochemical LLC, The Woodlands, and Texas.

The treating agent used in treating the amine catalyst is selected froma non-cyclic amide substituted with an isocyanate reactive group, aguanidine substituted with an isocyanate reactive group, a polyetheramine adducted with a urea compound or a guanidine compound, a freeradical scavenger and a mixture thereof.

According to one embodiment, the treating agent is a non-cyclic amidesubstituted with an isocyanate reactive group represented by the generalformula (I):R—(NH)_(n)-A-X  (I)where X is NHR⁰,R and R⁰ are each independently hydrogen or a linear or branched C₁-C₃₀alkyl group having a hydrogen or methylene group substituted with anisocyanate reactive group selected from —OH, —NH, —NH₂ and —COOH,n is 0, 1, or greater than 1 andA is C═O with the proviso that at least one of R or R⁰ is other thanhydrogen. In one preferred embodiment, R or R⁰ is a linear or branchedC₁-C₁₀ alkyl group having a terminal hydrogen or a terminal methylenegroup substituted with an isocyanate reactive group selected from —OH,—NH₂ or —COOH.

According to one particular embodiment, the non-cyclic amide substitutedwith an isocyanate reactive group of the formula (I) is a compound whereR is a C₁-C₃₀ linear or branched alkyl group having a hydrogen ormethylene group substituted with —OH, R⁰ is hydrogen and n=1. In afurther embodiment, the non-cyclic amide substituted with an isocyanatereactive group of the formula (I) is a compound where R is a linear orbranched C₁-C₁₀ alkyl group having a terminal hydrogen or terminalmethylene group substituted with —OH, R⁰ is hydrogen and n=1.

In still another embodiment, the non-cyclic amide substituted with anisocyanate reactive group of the formula (I) is a compound where R is aC₁-C₃₀ linear or branched alkyl group having a hydrogen or methylenegroup substituted with —NH, R⁰ is hydrogen and n=1. In a furtherembodiment, the non-cyclic amide with an isocyanate reactive group ofthe formula (I) is a compound where R is a linear or branched C₁-C₁₀alkyl group having a hydrogen or methylene group substituted with —NH,R⁰ is hydrogen and n=1.

In yet another embodiment, the non-cyclic amide substituted with anisocyanate reactive group of the formula (I) is a compound where R is aC₁-C₃₀ linear or branched alkyl group having a hydrogen or methylenegroup with —NH₂, R⁰ is hydrogen and n=1. In a further embodiment, thenon-cyclic amide with an isocyanate reactive group of the formula (I) isa compound where R is a linear or branched C₁-C₁₀ alkyl group having aterminal hydrogen or terminal methylene group substituted with —NH₂, R⁰is hydrogen and n=1.

According to another embodiment, the non-cyclic amide substituted withan isocyanate reactive group of the formula (I) is a compound where R isa C₁-C₃₀ linear or branched alkyl group having a hydrogen or methylenegroup substituted with —COOH, R⁰ is hydrogen and n=1. In a furtherembodiment, the non-cyclic amide with an isocyanate reactive group ofthe formula (I) is a compound where R is a linear or branched C₂-C₁₀alkyl group having a terminal hydrogen or terminal methylene groupsubstituted with —COOH, R⁰ is hydrogen and n=1.

In still another embodiment, the treating agent is a guanidinesubstituted with an isocyanate reactive group represented by the generalformula (II):R¹R²N-A-X  (II)where X═NHR³,R¹, R², and R³ are each independently hydrogen, a linear or branchedC₁-C₃₀ alkyl group of which a hydrogen atom may be further replaced witha substituent group, a C₅-C₁₅ cyclic group of which a hydrogen atom maybe further replaced with a substituent group, and

A is C═NH with the proviso that at least one of R¹, R² or R³ is a linearor branched C₁-C₃₀ alkyl group or a C₅-C₁₅ cyclic group each of whichhaving a hydrogen or methylene group substituted with an isocyanatereactive group selected from —OH, —NH, —NH₂ and —COOH.

Examples of substituent groups include a C₁-C₁₀ alkyl group, a C₃-C₈carbocyclic group, a C₁-C₁₀ alkoxy group, an aromatic hydrocarbon grouphaving six to ten carbon atoms, halogen or a nitro.

In another embodiment, the treating agent is a polyether amine adductedwith a urea compound or a guanidine compound. In one particularembodiment, the polyether amine adducted with a urea compound or aguanidine compound may be represented by the general formula (III):R⁴—NH-A-NH₂  (III)where R⁴ is a linear or branched alkoxylated polyether polyamine, andA is C═O or C═NH.

The linear or branched alkoxylated polyether polyamine may be preparedby means well known in the art. For example, the alkoxylated polyetherpolyamine may be prepared by reacting a polyether polyamine with one ormore low molecular weight alkylene oxides, such as ethylene oxide,propylene oxide, butylene oxide, or mixtures thereof, at a temperaturefrom about 100°-110° C. and at a pressure of about 60 psig in thepresence of an alkaline catalyst. The polyether polyamine may bealkoxylated to varying degrees. In one embodiment, the resultingalkoxylated polyether polyamine has an alkylene oxide content less thanabout 90 percent. The alkoxylated polyether polyamine may then bereacted with a urea compound or guanidine compound with heat over aperiod of time to form the respective adduct.

In one particular embodiment, R⁴ is an alkoxylated polyether polyaminerepresented by the general formula (IV):

where w is an integer ranging from about 1.5 to about 150. In anotherembodiment, w is an integer ranging from about 2 to about 75. In stillanother embodiment, w is an integer ranging from about 2.5 to about 70.

In another embodiment, R⁴ is an alkoxylated polyether polyaminerepresented by the general formula (V)

where r is an integer ranging from about 1.5 to about 50 and the sum ofq+s ranges from about 0.5 to about 8. In another embodiment, r is aninteger ranging from about 2 to about 40 and the sum of q+s ranges fromabout 1 to about 6.

In still another embodiment, R⁴ is an alkoxylated polyether polyaminerepresented by the general formula (VI):

where y is an integer ranging from about 1.5 to 4. In anotherembodiment, y is an integer ranging from about 2 to about 3.

In a further embodiment, R⁴ is an alkoxylated polyether polyaminerepresented by the general formula (VII):

where k is 0 or 1,B is hydrogen or an ethyl group, and(h+i+j) is an integer from about 4 to 100.

Examples of commercially available alkoxylated polyether polyamines arethe JEFFAMINE® D Series, ED Series, T Series and EDR Series amines(Huntsman Petrochemical LLC).

According to another embodiment, the treating agent is a free radicalscavenger. The free radical scavenger include compounds such as, but notlimited to, methimazole, phenyl methimazole, and derivatives thereof;allupurinol, propyl thiouracil, glutamine, diaminobenzylamine;nicotinamide; hindered phenols or hindered aliphatic or aromatic amines;and natural antioxidants such as Vitamin C, Vitamin E and/orglutathione. According to one embodiment, the free radical scavenger isa sterically hindered phenol. The term “sterically hindered phenol” asused herein means that the phenol in positions 2 and 6 of the aromaticring has substituents which, on the basis of their three-dimensionalsize, shield the OH group of the phenolic ring and result in anattenuated reactivity. In one particular embodiment, the stericallyhindered phenol is a compound having the formula (VIII):

where R⁵, R⁶ and R⁷ are independently selected from H or a C₁-C₁₀ alkylgroup and R⁸ is H or a C₁-C₁₂ alkyl group.

In one embodiment, R⁵, R⁶ and R⁷ are independently selected from H or aCH₃ group and R⁸ is H or a C₁-C₄ alkyl group. In still anotherembodiment, R⁵, R⁶ and R⁷ are each a CH₃ group and R⁸ is H, a methylgroup, an ethyl group, a propyl group or an isopropyl group.

Examples of such compounds having formula (VIII), include, but are notlimited to, 2,6-di-t-butyl-4-methyl phenol, 2,6-di-t-butyl-4-isopropylphenol, 2,6-di-t-butyl-4-ethyl phenol, 2,4-dimethyl-6-octyl phenol,2,6-di-t-butyl-4-n-butyl phenol and 2,4-dimethyl-6-t-butyl phenol.

In yet another embodiment, the treating agent is a mixture of at leastone of a non-cyclic amide substituted with an isocyanate reactive group,a guanidine substituted with an isocyanate reactive group, a polyetheramine adducted with a urea compound or guanidine compound describedabove with a sterically hindered phenol described above.

In some embodiments, the catalyst mixture of the amine catalyst and thetreating agent is solid. Therefore a solvent may also be added whenforming the catalyst mixture. The solvent is not limited and may includewater, high molecular weight polyols, butanediol, alcohols, such aslower carbon chain alcohols, for example, isopropyl alcohol, ethanol,n-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, n-amyl alcohol,sec-amyl alcohol, n-hexyl alcohol, and sec-hexyl alcohol; lower carbonchain alcohols that have been alkoxylated with ethylene oxide (EO),propylene oxide (PO) or butylene oxide (BO), for example, n-butanol+1EO,n-butanol+2EO, n-butanol+3EO, n-hexanol+6EO, 2-ethylhexanol+2EO andiso-butanol+3EO, alcohol ethers, polyalkylene alcohol ethers, such asethylene glycol monobutyl ether, polyalkylene glycols, such as ethyleneglycol and propylene glycol, poly(oxyalkylene) glycols, such asdiethylene glycol, poly(oxyalkylene) glycol ethers, or any mixturesthereof. In one embodiment, the amount of solvent added may be an amountnecessary to give a solids weight ratio of about 5-95% by weight. Inanother embodiment, the amount of solvent added may be an amount to givea solids weight ratio of about 10-80% by weight.

In one embodiment, the amine catalyst is treated by mixing it with thetreating agent and optional solvent to form a catalyst mixture and thensubjecting the catalyst mixture to conditions such that the level ofaldehyde impurities in the amine catalyst is reduced.

According to one embodiment, such conditions include maintaining thecatalyst mixture at approximately room temperature for a few hours to afew days. In one particular embodiment, the catalyst mixture ismaintained at room temperature for at least about 3 hours. In anotherparticular embodiment, the catalyst mixture is maintained at roomtemperature for at least about 6 hours. In still another embodiment,such conditions include maintaining the catalyst mixture at roomtemperature for at least about 12 hours, while in another embodimentsuch conditions include maintaining the catalyst mixture at roomtemperature for at least about 24 hours.

In other embodiments, a temperature higher than room temperature may beused to accelerate the removal of aldehydes from the catalyst mixture.Any temperature up to a temperature at which the amine catalyst degradesmay be used. In one embodiment, the catalyst mixture is maintained at atemperature between about 25°-200° C.: for at least about 3 hours, inanother embodiment for at least about 6 hours, in still anotherembodiment for at least about 12 hours, and yet in still anotherembodiment for at least 24 hours. In another embodiment, the catalystmixture is maintained at a temperature between about 60°-150° C.: for atleast about 3 hours, in another embodiment for at least about 6 hours,in still another embodiment for at least about 12 hours, and yet instill another embodiment for at least about 24 hours. In still anotherembodiment, the catalyst mixture is maintained at a temperature betweenabout 80°-120° C.: for at least about 3 hours, in another embodiment forat least about 6 hours, in still another embodiment for at least about12 hours, and yet in still another embodiment for at least about 24hours.

In other embodiments, the catalyst mixture may be maintained at roomtemperature or a higher temperature such as described above and atatmospheric pressure or at a pressure up to about 3 atmosphere: for atleast about 3 hours, in another embodiment for at least about 6 hours,in still another embodiment for at least about 12 hours, and yet instill another embodiment for at least about 24 hours.

In some embodiments, it's generally sufficient to treat the aminecatalyst with about 0.005%-15% by weight treating agent based on thetotal weight of the catalyst mixture. In another embodiment, the aminecatalyst may be treated with about 0.01%-10% by weight treating agentbased on the total weight of catalyst mixture. In yet anotherembodiment, the amine catalyst may be treated with about 0.5%-5% byweight treating agent based on the total weight of catalyst mixture. Instill another embodiment, the amine catalyst may be treated with up toabout 10% by weight treating agent, while in other embodiments it may betreated up to about 7.5% by weight treating agent, each of which arebased on the total weight of the catalyst mixture. In a furtherembodiment, the amine catalyst may be treated with at least about 0.05%by weight treating agent, in other embodiments it may be treated with atleast about 1% by weight treating agent, each of which are based on thetotal weight of the catalyst mixture.

In still another embodiment, a formulation containing the amine catalysttogether with other components useful in a polyurethane materialformation reaction, for example, a polyol, a polyisocyanate, asurfactant, a blowing agent and/or other additives such as a cellstabilizer, crosslinking agent, chain extender, pigment, filler, flameretardant, mold release agent, plasticizers; acid scavenger; waterscavenger; cell regulator; dye; UV stabilizer; fungistatic orbacteriostatic substance and transition metal catalyst may be treatedwith the treating agent and subjected to the conditions similar to thosedescribed above such that the level of aldehyde impurities in theformulation are reduced. Thus, in one embodiment, the amine catalyst andother components useful in a polyurethane formation reaction are mixedwith the treating agent to form a formulation and then stored at roomtemperature or at a higher temperature of up to about 120° C.: for atleast about 3 hours, in another embodiment for at least about 6 hours,in still another embodiment for at least about 12 hours, and yet stillanother embodiment for at least about 24 hours.

Once the level of aldehyde impurities in the catalyst mixture orformulation described above has been reduced, the catalyst mixture orformulation may be used to make a polyurethane material that exhibitsreduced aldehyde emissions compared to a polyurethane material that hasbeen made from a catalyst mixture or formulation that has not beentreated in accordance with this disclosure. The catalyst mixture orformulation can be used to make polyurethane materials in the samemanner as untreated materials.

These methods are well known to those skilled in the art and can befound in, for example, U.S. Pat. Nos. 5,420,170, 5,648,447, 6,107,359,6,552,100, 6,737,471 and 6,790,872, the contents of which are herebyincorporated by reference. Various types of polyurethane materials canbe made such as rigid foams, flexible foams, semi-flexible foams,microcellular elastomers, backings for textiles, spray elastomers, castelastomers, polyurethane-isocyanurate foams, reaction injection moldedpolymers, structural reaction injection molded polymers and the like.

According to one embodiment, particular foam applications include foamsfor cushioning applications such as bedding and seating and foams forautomotive interiors such as flexible and semi-flexible foams forautomotive seating, in headrests, in dashboards and instrument panels,in armrests or in headliners.

In one particular embodiment, a polyurethane foam may be prepared bybringing together at least one polyol and at least one polyisocyanate inthe presence of the catalyst mixture to form a reaction mixture andsubjecting the reaction mixture to conditions sufficient to cause thepolyol to react with the polyisocyanate. The polyol, polyisocyanate andcatalyst mixture may be heated prior to mixing them to form the reactionmixture. In other embodiments, the polyol, polyisocyanate and catalystmixture are mixed at ambient temperature (for e.g. from about 15°-40°C.). Heat may be applied to the reaction mixture, but in mostembodiments, this is not necessary. The polyurethane foam may be made ina free rise (slabstock) process in which the foam is free to rise underminimal or no vertical constraints. Alternatively, molded foam may bemade by introducing the reaction mixture in a closed mold and allowingit to foam within the mold. The particular polyol and polyisocyanate areselected with the desired characteristics of the resulting foam. Othercomponents useful in making polyurethanes, such as those describedabove, may also be included to produce a particular type of foam.

According to one embodiment, the polyurethane material may be producedfrom the reaction of an A-side reactant with a B-side reactant. TheA-side reactant may comprise a polyisocyanate while the B-side reactantmay comprise a polyol and the catalyst mixture according to the presentdisclosure. In some embodiments, the A-side and/or B-side may alsocontain optional other components such as those described above.

The polyisocyanates suitable for use include unmodified polyisocyanates,modified polyisocyanates and isocyanate prepolymers. Suchpolyisocyanates include those represented by the formula Q(NCO)p where pis a number from 2-5, preferably 2-3 and Q is an aliphatic hydrocarbongroup containing 2-18 carbon atoms, a cycloaliphatic hydrocarbon groupcontaining 5-10 carbon atoms, an araliphatic hydrocarbon groupcontaining 8-13 carbon atoms, or an aromatic hydrocarbon groupcontaining 6-15 carbon atoms.

Examples of suitable polyisocyanates include, but are not limited to,ethylene diisocyanate; 1,4-tetramethylene diisocyanate;1,6-hexamethylene diisocyanate; 1,12-dodecane diisocyanate;cyclobutane-1,3-diisocyanate; cyclohexane-1,3- and -1,4-diisocyanate,and mixtures of these isomers; isophorone diisocyanate; 2,4- and2,6-hexahydrotoluene diisocyanate and mixtures of these isomers;dicyclohexylmethane-4,4′-diisocyanate (hydrogenated MDI, or HMDI); 1,3-and 1,4-phenylene diisocyanate; 2,4- and 2,6-toluene diisocyanate andmixtures of these isomers (TDI); diphenylmethane-2,4′- and/or-4,4′-diisocyanate (MDI); naphthylene-1,5-diisocyanate;triphenylmethane-4,4′,4″-triisocyanate;polyphenyl-polymethylene-polyisocyanates of the type which may beobtained by condensing aniline with formaldehyde, followed byphosgenation (crude MDI); norbornane diisocyanates; m- andp-isocyanatophenyl sulfonylisocyanates; perchlorinated arylpolyisocyanates; modified polyisocyanates containing carbodiimidegroups, urethane groups, allophnate groups, isocyanurate groups, ureagroups, or biruret groups; polyisocyanates obtained by telomerizationreactions; polyisocyanates containing ester groups; and polyisocyanatescontaining polymeric fatty acid groups. Those skilled in the art willrecognize that it is also possible to use mixtures of thepolyisocyanates described above.

Isocyanate-terminated prepolymers may also be employed in thepreparation of the polyurethane materials. Isocyanate prepolymers may beprepared by reacting an excess of polyisocyanate or mixture thereof witha minor amount of an active-hydrogen containing compound as determinedby the well-known Zerewitinoff test as described by Kohler in “Journalof the American Chemical Society,” 49, 3181 (1927).

The polyol may be a petroleum-derived polyol, a natural oil polyol or apolyol obtained from renewable natural resources such as vegetable oil.

Petroleum-derived polyols useful in producing a polyurethane materialaccording to the present disclosure include polyether polyol, polymerpolyols, and polyester polyols having 2 or more reactive hydroxylgroups. Polyether polyols include, for example, polyhydric alcohols suchas glycol, glycerin, pentaerythritol, and sucrose; aliphatic aminecompounds such as ammonia, and ethyleneamine; aromatic amine compoundssuch as toluene diamine, and diphenylmethane-4,4′-diamine; and/or apolyether polyol obtained by adding ethylene oxide or propylene oxide toa mixture of above-mentioned compounds. A polymer polyol is exemplifiedby a reaction product of a polyether polyol with ethylenic unsaturatedmonomer, such as butadiene, acrylonitrile, and styrene, the reactionbeing conducted in the presence of a radical polymerization catalyst.Polyester polyols include those which are produced from a dibasic acidand a polyhydric alcohol such as, for example, polyethyleneadipate andpolyethyleneterephthalates which may include those products reclaimedfrom waste materials.

Polyols from inexpensive and renewable resources may also be used andare highly desirable since they minimize the depletion of fossil fueland other non-sustainable resources. Natural oils consist oftriglycerides of saturated and unsaturated fatty acids. One natural oilpolyol is castor oil, a natural triglyceride of ricinoleic acid. Othernatural oils need to be chemically modified to introduce sufficienthydroxyl content to make them useful in the production of polyurethanematerials. There are two chemically reactive sites that can beconsidered when attempting to modify natural oil into a usefulpolyol: 1) the unsaturated sites (double bonds); and 2) the esterfunctionality. Unsaturated sites present in natural oil can behydroxylated via epoxidation, followed by ring opening orhydroformilation, followed by hydrogenation. Alternatively,trans-esterification can also be utilized to introduce OH groups innatural oil. The chemical process for the preparation of natural polyolsusing an epoxidation route involves a reaction mixture that requiresepoxidized natural oil, a ring opening acid catalyst and a ring opener.Epoxidized natural oils include epoxidized plant-based oils (epoxidizedvegetable oils) and epoxidized animal fats. The epoxidized natural oilsmay be fully or partially epoxidized and these oils include soybean oil,corn oil, sunflower oil, olive oil, canola oil, sesame oil, palm oil,rapeseed oil, tung oil, cotton seed oil, safflower oil, peanut oil,linseed oil and combinations thereof. Animal fats include fish, tallowand lard. These natural oils are triglycerides of fatty acids which maybe saturated or unsaturated with various chain lengths from C₁₂ to C₂₄.These acids can be: 1) saturated: lauric, myristic, palmitic, steric,arachidic and lignoceric; 2) mono-unsaturated: palmitoleic, oleic, 3)poly-unsaturated: linoleic, linolenic, arachidonic. Partially or fullyepoxidized natural oil may be prepared when reacting peroxyacid undersuitable reaction conditions. Examples of peroxyacids utilized in theepoxidation of oils have been described in WO 2006/116456 A1; herebyincorporated by reference. Ring opening of the epoxidized oils withalcohols, water and other compounds having one or multiple nucleophilicgroups can be used. Depending on the reaction conditions,oligomerization of the epoxidized oil can also occur. Ring openingyields a natural oil polyol that can then be used in the manufacture ofpolyurethane materials. In the hydroformilation/hydrogenation process,the oil is hydroformylated in a reactor filled with a hydrogen/carbonmonoxide mixture in the presence of a suitable catalyst (typicallycobalt or rhodium) to form an aldehyde which is hydrogenated in thepresence of cobalt or nickel catalyst to form a polyol. Alternatively,polyol from natural oil can be produced by trans-esterification with asuitable poly-hydroxyl containing substance using an alkali metal oralkali earth metal base or salt as a trans-esterification catalyst. Anynatural oil or alternatively any partially hydrogenated oil can be usedin the transesterification process. Examples of oils include, but arenot limited to, soybean, corn, cottonseed, peanut, castor, sunflower,canola, rapeseed, safflower, fish, seal, palm, tung, olive oil or anyblend thereof. Any multifunctional hydroxyl compound can also be usedsuch as lactose, maltose, raffinose, sucrose, sorbitol, xylitol,erythritol, mannitol, or any combination.

In one particular embodiment, in addition to the polyol component andcatalyst mixture, the B-side reactant optionally comprises one or moreadditives including, but not limited to: blowing agents; crosslinkingagents, flame retardants; plasticizers; internal mold release agents;surfactants; acid scavengers; water scavengers; cell regulators;pigments; dyes; UV stabilizers; fungistatic or bacteriostaticsubstances; fillers and mixtures thereof.

Examples of blowing agents include, but are not limited to, water,liquid carbon dioxide, a hydrofluorocarbon, methyl isobutyl ketone, alow-boiling hydrocarbon such as pentane or cyclopentane, methylenechloride, a carbonate of an amine, or mixtures thereof.

Examples of crosslinking agents include, but are not limited to,ethylene glycol, diethylene glycol, triethylene glycol, propyleneglycol, 1,3-propanediol, 1,4-butandiol, 1,6-hexanediol, glycerol, andtrimethylolpropane.

Examples of flame retardants (which, as the term is used herein, alsoinclude smoke suppressants and other known combustion modifiers),include phosphonates, phosphites, and phosphates (such as dimethylmethylphosphonate, ammonium polyphosphate, and various cyclic phosphateand phosphonate esters known in the art); halogen-containing compoundsknown in the art (such as brominated diphenyl ether and other brominatedaromatic compounds); melamine; antimony oxides (such as antimonypentoxide and antimony trioxide); zinc compounds (such as various knownzinc borates); aluminum compounds (such as alumina trihydrate); andmagnesium compounds (such as magnesium hydroxide).

Internal mold release agents are compounds that may be added to assistin the removal of the polyurethane material from a mold. Suitableinternal mold release agents include those based at least in part onfatty acid esters, metal and/or amine salts of carboxylic acids, amidocarboxylic acids, phosphorus-containing acids, boron-containing acids,amidines, and neutralized esters prepared from certain amine-startedtetrahydroxy compounds as described in U.S. Pat. No. 5,208,268. Alsosuitable are water based and solvent based mold release agents, such asthose containing naphthalene and paraffin wax.

Surfactants (or surface-active agents) include emulsifiers and foamstabilizers, such as silicone surfactants known in the art, for example,polysiloxanes, as well as various amine salts of fatty acids, such asdiethylamine oleate or diethanolamine stearate, as well as sodium saltsof ricinoleic acids.

Acid scavengers are compounds that may be added to control the acidityand water concentration. Preferred acid scavengers include variousorthoesters, such as trimethyl orthoformate, carbodiimides, such as2,2′,6,6′-tetraisopropyldiphenylcarbodiimide, and epoxides, such as3,4-epoxycyclohexylmethyl 3,4-epoxy-cyclohexylcarboxylate.

Water scavengers (or moisture scavengers) are compounds that may beadded to maintain a low water content in the compositions of the presentinvention. Suitable water scavengers include alkali aluminosilicates.

Fillers and/or reinforcing substances, include barium sulfate, calciumcarbonate, calcium silicate, aluminum hydroxide, titanium dioxide,clays, fly ash, kieselguhr, mica, glass fibers, liquid crystal fibers,glass flakes, glass balls, hollow microspheres made of glass, alumina,silicas, etc., aramide fibers, and carbon fibers.

According to one embodiment, the polyurethane material may be preparedin a one-step process in which an A-side reactant is combined with aB-side reactant. The A-side may include the polyisocyanate or mixture ofpolyisocyanates. Different polyisocyanates may be selected to createdifferent properties in the final product. The B-side may be a solutionincluding at least one polyol and the catalyst mixture of the presentdisclosure and optionally additives.

The polyurethane materials produced having reduced aldehyde emissionsmay be used in a variety of applications, such as, a precoat; a backingmaterial for carpet; building composites; insulation; spray foaminsulation; applications requiring use of impingement mix spray guns;urethane/urea hybrid elastomers; vehicle interior and exterior partssuch as bed liners, dashboards, door panels, and steering wheels;flexible foams (such as furniture foams and vehicle component foams);integral skin foams; rigid spray foams; rigid pour-in-place foams;coatings; adhesives; sealants; filament winding; and other polyurethanecomposite, foams, elastomers, resins, and reaction injection molding(RIM) applications.

In another embodiment, there is provided a packaged product comprising:a) a container having at least an outlet; and b) the catalyst mixture ofthe present disclosure within the container.

According to one embodiment, the packaged product of the presentdisclosure comprises a container having a closure means, such as a lid,cover, cap, or plug to seal the container. In another embodiment, thesealed container also has a nozzle or pour spout. The sealed containermay have the shape of a cylinder, oval, round, rectangle, canister, tub,square or jug and contains the catalyst mixture. In some embodiments,the sealed container is padded with an inert gas, such as nitrogen.

The container may be made from any material, such as steel, glass,aluminium, cardboard, tin-plate, plastics including HDPE, PP, PVC, PET,OPP, PE or polyamide and including mixtures, laminates or othercombinations of these. The catalyst mixture is dispensed from thecontainer through the outlet. In one embodiment, the catalyst mixture isdispensed from a nozzle when the nozzle is activated. In anotherembodiment, the catalyst is mixture is dispensed via a pour spout.

As described below, aldehydes, such as formaldehyde, can be reduced inthe amine catalyst with no processing requirements other than mixing theamine catalyst with the treating agent and subjecting the mixture tonormal storage conditions or elevated temperatures for a minimal amountof time.

EXAMPLES Example 1a. Treating Agent

2847 grams of JEFFAMINE® D-400 polyether amine and 893 grams of ureawere charged to a 5 liter flask equipped with a heating mantle, stirrer,temperature controller, nitrogen sparge tube, condenser and phosphoricacid ammonia trap. The material was heated to 124° C. Ammonia evolved inlarge amounts into the trap. The material was continually heated for 4.5hours, with a slow raising of the temperature to 150° C. until theevolution of ammonia ceased. The material was analyzed by NMR and foundto contain both primary amine and urea end groups with a trace of ureastill present.

Example 1b. Treating Agent

500 grams of JEFFAMINE® D-2000 polyether amine was reacted with 326.3grams of urea in the apparatus used in Example 1a. The temperature wasslowly raised to 135° C. over eleven hours. The material obtained was athick clear liquid that was pourable at 80° C. After analysis by NMR, itwas found to contain both primary amine and urea end groups.

Example 1c. Treating Agent

6123 grams of monoethanol amine was reacted with 591 grams of urea inthe apparatus described in Example 1a. The material was heated slowly to80° C. with the temperature being increased over a 6 hour period to 112°C. to control the evolution of ammonia. The material was a waxy solidand analyzed by NMR and found to be ethanolurea.

Example 2. Control

N,N,N′-trimethyl-N′-hydroxyethylbisaminoethylether (JEFFCAT® ZF-10 aminecatalyst) was analyzed and found to have a PtCo color of 131.6 and aformaldehyde content of 89.3 ppm. The amine catalyst was then placed ina one liter flask equipped with a nitrogen sparge tube, mixer,temperature controller, K head and condenser and distilled under vacuum.After analysis, the amine catalyst was found to have a PtCo color of16.6 and a formaldehyde content of 96.1 ppm.

The formaldehyde measurements in this Example, as well as the otherExamples, can be performed using known standard analytical tests, suchas by trapping the formaldehyde on a media treated with dinitrophenylhydrazine, desorbing with solvent, and measuring by liquidchromatography.

Example 3. Control

1000 grams of JEFFCAT® ZF-10 amine catalyst was placed in the samedistillation apparatus used in Example 2. 400 grams of deionized waterwas then added to the flask and the mixture was distilled. Afteranalysis, the amine catalyst was found to have a PtCo color of 18.4 anda formaldehyde content of 62.8 ppm.

Example 4. Amine Catalyst+Treating Agent

1000 grams of JEFFCAT® ZF-10 amine catalyst was added to thedistillation apparatus used in Example 2 along with 400 grams ofdeionized water. 5 grams of 2,6-di-t-butyl-4-isopropyl phenol was thenadded and the mixture was distilled. After analysis, the amine catalystwas found to have a PtCo color of 31.6 and a formaldehyde content of31.7 ppm.

Example 5. Amine Catalyst+Treating Agents

1000 grams of JEFFCAT® ZF-10 amine catalyst was added to thedistillation apparatus used in Example 2 along with 400 grams ofdeionized water. 5 grams of 2,6-di-t-butyl-4-isopropyl phenol and 20grams of a 50% w/w aqueous solution of ethanol urea from Example 1c wereadded and the mixture was distilled. After analysis, the amine catalystwas found to have a PtCo color of 19.2 and a formaldehyde content of27.2 ppm.

The amine catalyst was then further treated with an additional 5 gramsof 2,6-di-t-butyl-4-isopropyl phenol and 10 grams of a 50% aqueousethanolurea from Example 1c and the mixture held at 100° C. for 24hours. The amine catalyst was then analyzed and found to have aformaldehyde content of 23.7 ppm.

Example 6. Amine Catalyst+Treating Agent

1000 grams of JEFFCAT® ZF-10 amine catalyst was added to thedistillation apparatus used in Example 2 along with 400 grams ofdeionized water. 20 grams of the treating agent prepared in Example 1awere added and the mixture was held at 100° C. for 24 hours. The aminecatalyst was analyzed and found to have a formaldehyde content of 23.7ppm.

Example 7. Low Density Foam

A low density wall spray foam was prepared by mixing 48.7 parts byweight of a A-side resin comprising Rubinate® M isocyanate with 51.3parts by weight of an B-side formulation containing the followingcomponents:

Control i B-Side pbw pbw JEFFOL ® SD-441* 12.3 12.3 JEFFOL ® G31-35*15.2 15.2 Water 22.0 22.0 Fire Retardant 25.0 25.0 Blend* Silstab ® 27601.0 1.0 Surfonic ® N-95* 15.0 13.0 JEFFCAT ® ZR-50* 0.5 0.5 JEFFCAT ®Z-110* 4.0 4.0 JEFFCAT ® S-127* 5.0 5.0 Treating Agent 1a 2.0 Creamtime, sec 5 4.0 Top of cup time, sec 6.3 5.5 Tack free time, sec 9.9 9.3Rise time, sec 10.3 10.7 *JEFFOL ® SD-441 is a sucrose polyol availablefrom Huntsman International LLC JEFFOL ® G31-35 is a glycerol initiatedEO capped triol available from Huntsman International LLC Fire RetardantBlend is a mixture of brominated and chlorinated phosphate esterSilstab ® 2760 is a silicone surfactant available from Siltech Corp.Surfonic ® N-95 is an ethoxylated nonyl phenol emulsifier available fromHuntsman International LLC JEFFCAT ® ZR-50, JEFFCAT ® Z-110 andJEFFCAT ® S-127 are tertiary amine catalysts available from HuntsmanInternational LLC

Good quality foam, with no detectable odor, was produced having anominal density of 0.5 psf for formulations containing no treatedcatalyst and those containing a treated catalyst. Thus, use of thetreated catalyst during the production of foam does not adversely affectfoam quality.

Consideration must be given to the fact that although this disclosurehas been described and disclosed in relation to certain preferredembodiments, obvious equivalent modifications and alterations thereofwill become apparent to one of ordinary skill in this art upon readingand understanding this specification and the claims appended hereto. Thepresent disclosure includes the subject matter defined by anycombination of any one of the various claims appended hereto with anyone or more of the remaining claims, including the incorporation of thefeatures and/or limitations of any dependent claim, singly or incombination with features and/or limitations of any one or more of theother dependent claims, with features and/or limitations of any one ormore of the independent claims, with the remaining dependent claims intheir original text being read and applied to any independent claim somodified. This also includes combination of the features and/orlimitations of one or more of the independent claims with the featuresand/or limitations of another independent claim to arrive at a modifiedindependent claim, with the remaining dependent claims in their originaltext being read and applied to any independent claim so modified.Accordingly, the presently disclosed invention is intended to cover allsuch modifications and alterations, and is limited only by the scope ofthe claims which follow, in view of the foregoing and other contents ofthis specification.

What is claimed is:
 1. A method for reducing the aldehyde content in anamine catalyst comprising (i) mixing an amine catalyst containing one ormore aldehyde impurities and a treating agent selected from a polyetheramine adducted with a urea compound or a guanidine compound to form acatalyst mixture and (ii) subjecting the catalyst mixture to conditionssuch that the level of aldehyde impurities in the catalyst mixture arereduced, wherein the polyether amine adducted with a urea compound or aguanidine compound is represented by the general formula (III):R⁴—NH-A-NH₂  (III) where R⁴ is a linear or branched alkoxylatedpolyether polyamine, and A is C═O or C═NH.
 2. The method of claim 1wherein the conditions include maintaining the catalyst mixture atapproximately room temperature for at least about 3 hours.
 3. The methodof claim 1 wherein R⁴ is an alkoxylated polyether polyamine representedby the general formula (IV):

where w is an integer ranging from about 1.5 to about
 150. 4. The methodof claim 1 wherein the treating agent further comprises a free radicalscavenger comprising a sterically hindered phenol having the formula(VIII):

where R⁵, R⁶ and R⁷ are independently selected from H or a C₁-C₁₀ alkylgroup and R⁸ is H or a C₁-C₁₂ alkyl group.
 5. The method of claim 4wherein R⁵, R⁶ and R⁷ are independently selected from H or a CH₃ groupand R⁸ is H or a C₁-C₄ alkyl group.
 6. The method of claim 4 wherein R⁵,R⁶ and R⁷ are each a CH₃ group and R⁸ is H, a methyl group, an ethylgroup, a propyl group or an isopropyl group.
 7. A method, for reducingthe aldehyde content in an amine catalyst comprising (i) mixing an aminecatalyst containing one or more aldehyde impurities and a treating agentselected from a polyether amine adducted with a urea compound or aguanidine compound to form a catalyst mixture and (ii) subjecting thecatalyst mixture to conditions such that the level of aldehydeimpurities in the catalyst mixture are reduced, wherein the polyetheramine adducted with a urea compound or a guanidine compound isrepresented by the general formula (III):R⁴—NH-A-NH₂  (III) where R⁴ is a linear or branched alkoxylatedpolyether polyamine, and A is C═O or C═NH and wherein the conditionsinclude maintaining the catalyst mixture at a temperature of betweenabout 60°−150° C. for at least about 3 hours.